By: Jake Price (UGA Extension, Lowndes County, GA – jprice@uga.edu) and Dr. Kim Bowman (Rootstock geneticist, Ft. Pierce, FL – Kim.Bowman@usda.gov)

Purpose: Identify the best commercially-available rootstocks for ‘Owari’ satsumas, based upon effects on fruit yield, fruit quality, cold-hardiness, tree health, fruit size, and tree size.

Background: In 2014, Lowndes Extension began growing ‘Owari’ satsuma trees on standard and new hybrid rootstocks in a replicated research plot to help citrus growers determine what rootstocks to use with satsumas. In addition to commonly used Poncirus trifoliata rootstocks such as ‘Rubidoux’, ‘Rich 16-6’, and ‘Flying Dragon’, recently released trifoliate hybrid rootstocks developed by Dr. Kim Bowman of the USDA-ARS in Ft. Pierce, Florida are being evaluated. Each year, as the trees mature, data is being collected to show how each of these rootstocks perform with the ‘Owari’ satsuma scion.  

Comments on 2020 DATA: The data below shows tree yields, marketable fruit percentage, Brix, fruit size, and tree canopy volume. Trees on the rootstocks Sour Orange, US-897, and US-852 were planted in 2015 and trees on Rubidioux were planted in 2016.  This is the first year Rubidoux was allowed to fruit. Overall the percentage of marketable fruit was only 57% in 2020 compared to 81% in 2019.  Trees on several rootstocks had less fruit per tree than 2019 which resulted in higher fruit weights leading to more cull fruit. 

Location:  Valdosta, GA

Number Rootstocks: 10

Experimental Design: Randomized complete block, 6 reps × 1 tree/rootstock

Spacing: 12 ft. × 20 ft. (3.6 m × 6.1 m)